Pressure sealing plug for cartridge case



y 1960 J. J. BRADY 2,935,945

PRESSURE SEALING PLUG FOR CARTRIDGE CASE Filed March 28, 1958 .INVENTOR. JAMES J. BRADY BY y wajwsw/eyzw PRESSURE snALmo gr t io FoR CARTRIDGE w James J. Brady, Conshohocken, Pa., assignor to the United 1 States of America as represented by the Secretary of the Army Y Application March 28, 1958, Serial No. 724,781

, V .1 Claim. c1.102- -43 (Granted under Title 35, US. Code 1952 sec. 266) The invention described herein may be manufactured and used by .or for the Government for governmental purposes without the payment of any royalty thereon.

' This invention relates to cartridges of the type wherein a propellant is introduced into the cartridge case through an opening which is usually in the base of the case and has heretofore been closed by a single-piece plug threaded into it.

In the use of such cartridges, it has been found that the case tends to expand and pull away from the plug,

when'pressure is built up inside it. This results in gas leakage, blowing of the plug, and serious damage to the. gun mechanism. In accordance with the present inven-' ftion, this ditficulty is avoided by the provision of a plug which is acted upon by the gaspressure to prevent leak age.

The invention will be better understood fromthe fol- Qlowing descriptionwhen considered in connection with the accompanying drawing and its scope is indicated by the appended claims.

The single figure of the drawing illustrates a generally axial cartridge which includes a case 10 and a generally axial primer 11. The base of the case 10 has an opening 12 through. which a propellant is introduced into it. Threaded into this opening 12 is an annulus 13 of brass or other yieldable or deformable material of the shape illustrated and having an internal diameter of decreasing I size outwardly and toward an axis of the opening. Held in'this annulus 13 by its tightness of fit i.e. frictionally, is the plug 14 of a rigid material such as steel shaped as shown in drawing and tapered correspondingto the United States Patent taper inside annulus 13. Plug 14 has anexternal diam; eter decreasing in size outwardly toward an axis of the introduced into the cartridge case, anda threaded closure for said opening, the combination therewith of an. improvement in said closure to maintain the closure threads engaged with threads in the Wall of the opening-andto insure that said closure will not be blown out by internal, '1 pressure when said base and side-walls are expanded-by said internal pressure, said improvement including a brass deformable annulus threaded within said opening and provided with a central conical recess therein having a diameter or" decreasing size longitudinally and outwardly: of the cartridge case, and a conical steel plug held in said"; recess with its conical surface generally parallel to thev Walls of the conical recess in the annulus,:said annulus" also surrounding substantially the full axial length of "said plug whereby on generation of internal pressure by detonation of the propellant said side walls and base of the cartridge case are expanded and said steel plug is moved to expand said annulus and maintain its threads in engageg ment with the threaded opening.

References Cited inthe file of this. patent UNITED STATES PATENTS 1,229,049 Dessinger crimes, 1917 1,494,718 Semple May 20,- 1924 2,314,736 Sabol Mar. 23, 1943 2,396,469 Meigs Mar. 12, 1946 2,538,288 Whitsel Ja -1'6, 1951 FQREIGN PATENTS I 1 j 319,804 'France oer." 1, 1902 Patented 

